Portable and modular cardiopulmonary bypass apparatus and associated aortic balloon and associated method

ABSTRACT

The selective and differential perfusion method includes withdrawing blood through a cannula introduced into a patient&#39;s blood vessel. The temperature of such blood is controlled and flowed through an arterial cannula introduced into a selected arterial vessel of the patient for a sufficient time and at a sufficient flow rate to change the temperature of at least a portion of the patient&#39;s body. An aortic balloon catheter is introduced into the aorta of the patient to establish fluid communication through the catheter lumen between an external location and an aortic location which is disposed in a preferential flow relationship with a selected branch artery of the aorta leading to a selected region of the patient&#39;s body. A balloon mounted on the exterior of said aortic catheter is positioned at a balloon location spaced longitudinally from the aortic location and inflated to resist blood flow while a fluid is communicated through the catheter lumen between the external location and the aortic location. The aortic balloon catheter may further include a second lumen introduced into the aorta to establish a preferential flow relationship with a second branch artery leading to a second region of the patient&#39;s body and wherein the balloon location is disposed between the selected branch artery and the second branch artery.

This application is a Continuation of application Ser. No. 08/637,861filed Apr. 25, 1996, now U.S. Pat. No. 5,820,593, which in turn is aContinuation of application Ser. No. 08/396,474 filed Mar. 2, 1995 (nowabandoned) which is a Continuation of application Ser. No. 08/134,769filed Oct. 12, 1993 (now abandoned) which in turn is a divisional ofapplication Ser. No. 07/637,565 filed on Dec. 28, 1990 and which issuedas U.S. Pat. No. 5,308,320 on May 3, 1994, all of which have beenassigned to this assignee of this present application. Each of theseapplications, in their entirety, are hereby expressly incorporatedherein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a portable and modular cardiopulmonary bypassapparatus and more particularly it relates to a portable apparatus thatcan be used to effectively treat patients in suspected terminal statesor clinical death. The invention also includes an associated aorticballoon catheter and an associated method.

2. Background of the Invention

The development of external cardiopulmonary-cerebral resuscitation(CPCR) was initiated by one of the co-inventors herein, Dr. Peter Safar.This breakthrough revolutionized the then embryonic field of criticalcare medicine by allowing anyone anywhere to initiate life-savingprocedures. Since its introduction, it has been taught worldwide andused innumerable times on victims of cardiac arrest. It is standardprocedure worldwide in treating victims of heart arrest, asphyxiation orother lethal emergencies.

There are, however, limits to the application of standard CPCR becausesternal compression cannot reliably produce enough blood flow tomaintain viability of vital organs. Moreover, prolonged life support(PLS) after restoration of a heartbeat has its limits without theavailability of artificial circulation and oxygenation.

This need led to the development of emergency cardiopulmonary bypass(CPB). CPB permits the control of flow, pressure, temperature andoxygenation of the blood. See Safar et al., "Cardiopulmonary Bypass forEmergency Resuscitation after Prolonged Cardiac Arrest", AmericanJournal Of Emergency Medicine, 2:348, 1984.

It is known that periods of no-blood flow to the brain can seriouslyeffect brain function. Therefore, the key element in resuscitation is tostart life-saving procedures as quickly as possible after onset ofcardiac arrest. This invention relates to a method for selectively anddifferentially perfusing regions of a patient's body by using an aorticballoon catheter during cardiopulmonary bypass operations to effectivelytreat patients undergoing various cardiopulmonary procedures. There isno disclosure concerning using this device at the scene of an accidentor a heart attack.

Another advantage of CPB over CPCR is that CPB can be used inassociation with other techniques to prevent or correct derangementsencountered in terminal states and clinical death such as rapid bloodloss, blood gas derangements, temperature extremes and intoxication. CPBcan be used in association with methods to purify blood and to providehemoadsorption, plasma and blood cell apheresis. Other procedures thatcan be used in association with CPB are heating or cooling the blood andtotal body blood wash-out and blood replacement. Therefore, any CPBapparatus should be adapted to accommodate modules to accomplish theseprocedures.

Therefore, there is a need for methods to selectively and differentiallyperfuse regions of a patient's body using an aortic balloon catheterwhich is adapted to establish cardiopulmonary bypass of patients for thepurpose of assisting medical personnel in performing various medicalprocedures on such patients who may be experiencing any or all of theabove-described derangements. Further, such selective and differentialperfusion methods should incorporate application of the proceduresdescribed below for selectively and differentially perfusing andwithdrawing fluids respectively to and from such patients.

SUMMARY OF THE INVENTION

The selective and differential perfusion method includes withdrawingblood through a cannula introduced into a patient's blood vessel. Thetemperature of such blood is controlled and flowed through an arterialcannula introduced into a selected arterial vessel of the patient for asufficient time and at a sufficient flow rate to change the temperatureof at least a portion of the patient's body. An aortic balloon catheteris introduced into the aorta of the patient to establish fluidcommunication through the catheter lumen between an external locationand an aortic location which is disposed in a preferential flowrelationship with a selected branch artery of the aorta. A balloonmounted on the exterior of said aortic catheter is positioned at aballoon location spaced longitudinally from the aortic location andinflated to resist blood flow while a fluid is communicated through thecatheter lumen between the external location and the aortic location.

The selective and differential perfusion method further includespositioning a first lumen of an aortic balloon catheter to establishfluid communication with a first branch artery of the patient's aortaleading to a first region of a patient's body. A second lumen of thecatheter is positioned to establish fluid communication with a secondbranch artery of the patient's aorta leading to a second region. A bloodflow resisting balloon mounted on the catheter is positioned in theaorta between the first and second branch arteries and inflated toresist blood flow. Then, a first condition fluid and a second conditionfluid may be communicated between the first and second branch arteries,respectively.

It is an object of the invention to provide an apparatus for CPB whichis portable such that it can be used at the scene of an accident or of apatient having cardiac arrest or other life threatening emergency.

It is a further object of the invention to provide an apparatus thatprovides life saving CPB at the earliest possible time either inside oroutside a hospital.

It is a further object of the invention to provide a portable CPBapparatus that can be adapted to contain several blood conditioningmodules.

It is a further object of the invention to provide an aortic ballooncatheter module associated with the CPB apparatus to providedifferential perfusion of selective regions of a patient's body.

It is a further object of the invention to provide a massive bloodinfusor module to supplement or replace a patient's blood.

It is a further object of the invention to provide a blood heatexchanger to control the temperature of a patient's blood.

These and other objects of the invention will be more fully understoodfrom the following description of the invention with reference to thedrawings appended to this application.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the apparatus in a closed position readyfor transport to (i) the scene of an accident or (ii) a victim of heartarrest or other lethal emergency.

FIG. 1A is a rear elevational view of the apparatus in a closedposition.

FIG. 2 is a perspective view of the apparatus in an open position suchthat it is ready to be used on a trauma or heart attack victim.

FIG. 3 is a schematic view of the "core unit" of the apparatus showinghow and where the various modules are adapted to be attached thereto.

FIG. 4 is a perspective view of the aortic balloon catheter of theinvention with its outer covering removed for clarity of explanation.

FIG. 5 is a cross-sectional view of the catheter of the invention as itis in position in the aorta of a human.

FIG. 6 is a cross-sectional view taken along line 6--6 of FIG. 5.

FIG. 7 is a cross-sectional view taken along line 7--7 of FIG. 5.

FIG. 8 is a cross-sectional view taken along line 8--8 of FIG. 5.

FIG. 9 is a cross-sectional view taken along line 9--9 of FIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENT

As used herein, the term "portable" is defined as being able to betransported with relative ease by one adult of normal strength and size.Also, as used herein, the term "patient" refers to any member of theanimal kingdom, including but not limited to human beings.

Referring to FIGS. 1 and 1A, the apparatus of the invention is shown.The apparatus consists of a base 12, a first sidewall 14, a secondsidewall 16, a back wall 18 and a front wall 20. The apparatus furtherconsists of a lid 30 which is connected by a hinge (not shown) tosidewall 14 and which is further connected to the second sidewall 16 bytwo locking means 32 and 34. The top wall 36 of the lid 30 is equippedwith a carrying handle 38 to facilitate transporting the apparatus.

Connected to the underside of the base 12 are four wheels 40, 42, 44 and45. The wheels are mounted on axles (not shown) that are connected to apair of axle supports such as for example 46 and 48 of wheel 40. Ifdesired, locking means can be provided on the wheels. The opposite endsof the axle supports 46 and 48 are attached to the base 12 as by weldingor the like.

The apparatus is preferably fifteen (15") inches in height, twenty (20")inches in length and twelve (12") inches in width. The unit ispreferably less than fifty (50) pounds in weight and is made ofshock-resistant light weight materials such as vacuum foamed plastic. Itwill be appreciated that the dimensions, weight and materials used arepresented as examples only and the invention is not limited thereby,except that the apparatus should be portable as defined hereinabove.

Referring now to FIG. 2, the apparatus is shown with the lid 30 openedand front wall 20 removed thus exposing the various devices used forlife-saving CPB. The lid 30 can be optionally provided to be rotated180° to form a substantially horizontal surface that can serve as a trayor stand for other modules and/or provide extra space for placing otheritems such as intubation, surgical and drug administration supplies. Adrawer 50 is also provided which is retractable from the base 12. Thedrawer 50 forms a surgical instrument tray when pulled away from theapparatus. The drawer 50 can contain items 51 required for vascularaccess. These items include vascular catheters and surgical instrumentssuch as scalpels, scissors, clamps and sutures. The apparatus is alsoprovided with a retractable I-V stand 60 which can be folded and storedin the cavity 62 of the apparatus formed by the base and sidewalls. Alsostored in the cavity can be a spare CPB circuit and sterile plasma orblood substitute bags for primary and initial fluid resuscitation.

Once the apparatus is positioned for use, retractable legs 64, 65, 66and 67 which are associated with each wheel 40, 42, 44 and 45 can beused. The retractable legs are pivotally mounted to the underside of thebase 12 of the apparatus. The retractable legs not only providestability for the apparatus when in use, they also provide extra heightand tilt. The tilt is provided by making legs 64 and 65 shorter inheight than legs 66 and 67. cannula assembly means 70 which is designedto be placed in a patient's venous blood vessel for withdrawing venousblood therefrom. The first cannula assembly means 70 as shown is a venaecavae cannula which can be inserted via the femoral vein and isnon-kinking, multihole, large bore, long, thin-walled and preferablyheparin bonded. One example of a commercial cannula assembly means is amodel made by Medtronics. The first cannula assembly means 70 has astylette and is insertable either by cut down of, for example, thefemoral vein or by a guidewire (Seldinger Technique) or both. The firstcannula assembly means 70 includes a tube 74 which flows blood into thepump 76. A stopcock 78 and T-tube 80 are provided on the tube 74 foradministration of drugs, sampling of venous blood or drawing of venousblood in the case of blood exchange. The I-V stand 60 can contain an I-Vbag 82 which is connected to a tube 84 that is in turn connected to thefirst cannula assembly means 70. It will be appreciated that the I-Vstand 60 can accommodate more than one I-V bag. Tube 84 as shown is alsoprovided with a stopcock 86 and T-tube 87.

The pump 76 receives the withdrawn venous blood from the patient andtransports this blood through the apparatus. The pump 76, as shown, ispreferably a non-occlusive centrifugal pump such as Model No. BF80 madeby Biomedicus Company of Eden Prairie, Minn., U.S.A. The pump 76preferably can pump up to ten (10) liters per minute. The pump 76 ismounted on a pump console 90 by means of an interchangeable pump base 91which will facilitate attachment of various pump heads. The pump console90 contains controls 92 and 94 to control the rpm of the pump 76 and theflow rate of the fluid through the pump 76, respectively. The pump rpmis displayed on meter 96 and the pump flow rate is displayed on meter98. In this way, the operator can control both of these functions of thepump 76.

The pump 76 is powered by either (i) an AC power source which isaccessed by a cord 101 and AC plug 102; (ii) a battery gel-pak 104 whichis mounted in the cavity 62 as is shown in the partially cut away viewof FIG. 2; or (iii) a hand crank 105 which engages the pump shaft ofpump 76 by means of a bendix gear (not shown). It will be appreciatedthat the AC power source as accessed by the cord 101 and plug 102 arepreferred to be used, however, if there is no ready AC power source, thebattery gel-pak 104 will provide the necessary power to run theapparatus. Finally, if an AC power source is not available and thebattery gel-pak is inoperable, the hand crank 105 can be used.

Another tubing means 110 is connected to the outlet end of the pump 76.This tubing means 110 runs through an electromagnetic flowmeter 112which is connected to the console and ultimately the flow rate control94 and display 90. The electronic signals from the flowmeter 112 aretransferred to the pump console 90, where they are converted to rpm andflow rate indications which are displayed on the rpm meter 96 and theflow rate meter 98.

Another tube 113 connects the electromagnetic flow meter 112 to theoxygenator 120. The oxygenator 120 is preferably a membrane oxygenator.The oxygenator 120 includes oxygen tanks 122 and 124 which are alsostored in the apparatus. The tanks preferably hold one thousand (1000)liters of oxygen which will provide over two hours of operatingcapacity. Because of the tilt of the apparatus due to the retractablelegs 64, 65, 66 and 67, the oxygenator 120 is obliquely positioned tomake the bubbles created therein rise to the top to facilitate removalof the air ("debubbling") from the oxygenated patient blood.

A second cannula assembly means 128 as shown includes a tube 130 thatreceives the oxygenated blood from the oxygenator 120 and returns it tothe patient's arterial system such as through the femoral artery. Thesecond cannula assembly means 128 includes a blood filter and bubbletrap 132 which filters bubbles and clots. The second cannula assemblymeans 128 can be a short twelve to eighteen French size arterial cannulawith multiple holes.

It will be appreciated that the entire circuit that is in contact withthe blood, with perhaps the exception of the pump 76 head which receiveshigh flows, is preferably heparin bonded. This will avoid systemicheparinazation of the patient, which as is known, can increase bleedingtendency in the patient. Heparin bonding is a patented procedure ownedby Medtronics.

In use, the apparatus is carried by qualified medical personnel to apatient in need of CPB. The retractable legs can be set to position theapparatus. The lid locking means 32 and 34 are released and the lid 30is opened. Patients in terminal state (severe shock or hypoxemia) orcardiac arrest who do not respond to standard resuscitative efforts overa reasonable period of time (usually minutes) would be approached by theCPB team. During ongoing standard resuscitation, femoral vessel accesswill be established, the venae cavae cannulated via the femoral vein andthe femoral artery cannulated--both either by cutdown or the so-called"Seldinger Technique" with use of needle and guidewire. During thevessel access procedure, another person is priming the CPB circuit withplasma substitute. The apparatus, however, can be preprimed (as will beexplained hereinafter with respect to FIG. 3). Initiation of CPB aftervessel access is done as rapidly as possible. Pump flow is initiatedwith the highest rpm possible and then adjusted depending on whetherthere is no flow or low flow of spontaneous circulation. All treatmentis "titrated" to the patient's monitored variables, which change rapidlyduring the reversal of terminal states or clinical death. Oncespontaneous circulation is started with or without defibrillatingcounter-shocks shocks and drug usage, the total bypass (controlledcirculation) via oxygenator is transformed into a partial bypass and assoon as clinically feasible the patient is weaned from bypass.

As explained hereinbefore, the apparatus can be adapted to include oneor more modules for conditioning the blood of the patient whileperforming CPB. The modules that can be adapted for use with theapparatus are (1) blood temperature controller, (2) blood volume infuserand exchanger, (3) blood purifying modules, (4) aortic balloon catheterand (5) arterial and venous oxygen monitors.

Referring to FIG. 3, a schematic diagram of the apparatus and the abovefive modules is shown. The core unit of the apparatus is shown. The coreunit consists of the patient first cannula assembly means 70 includingcannula tube 74, the pump 76, the pump console 90, the electromagneticflowmeter 112, the membrane oxygenator 120 (which includes the oxygentanks 122 and 124 not shown on FIG. 3) and the second cannula assemblymeans 128. The operation and use of the core unit of the apparatus wasexplained hereinabove with respect to FIGS. 1 and 2. The five modulesdiscussed hereinabove are provided in separately portable units for usewith the core unit of the apparatus. In this way, blood conditioning cantake place at the same time as CPB.

Also illustrated in FIG. 3 is a shunt circuit 150. The shunt circuitpermits recirculation of the priming fluid prior to opening up ofcirculation to the patient. The shunt circuit also permits control ofpriming fluids temperature (for example, for induction of hypothermiawith CPB) during vessel access, so that the first fluid entering thepatient is at the desired lower temperature. The opposite would hold fortreating hypothermic arrest, so that the first fluid entering thepatient is about five to ten degrees Centigrade (5°-10° C.) above bodytemperature to rewarm the patient.

The blood temperature controller module 200 is shown in FIG. 3. Theblood temperature controller module 200 is provided in a separate case.The blood temperature controller module 200 consists of miniaturizedfluid circuit with a pump 201 delivering temperature controlled warmedor cooled solution (usually water) through a blood heat exchanger 202.The pump 201 can preferably move up to ten (10) liters per minutethrough the exchanger 202. The solution is circulated through tubes 203and 204 (in the direction of the arrows) into the controller unit 205and the blood heat exchanger 202.

As is known, the warmed or cooled solution is passed through the heatexchanger 202 at the same time as the blood from the pump 76. Thecooling is accomplished by immersion of the solution in ice, CO₂ ice,blue gel ice container, or other suitable source 209. The solution canbe warmed by providing an electric immersion heater 211, for example.The solution and the blood do not contact each other but are separatedby a membrane which allows the temperature of the solution to controlthe temperature of the blood. The solution is continually circulatedthrough the controller unit 205 and the blood heat exchanger 202. Theheat exchanger unit is capable to lower the venous inflow bloodtemperature by at least five degrees Centigrade (5° C.) through the heatexchanger at a flow rate of ten (10) liters per minute to permit rapidinduction of mild, moderate or deep hypothermia for an adult. The pump201 preferably can move up to ten (10) liters of fluid per minutethrough the exchanger. The module would also contain a battery, athermometer to monitor the water temperature, temperature monitors forcontinuous display of the patient's nasopharyngeal or tympanic membranetemperature and esophageal temperature.

FIG. 3 shows the second module, a blood volume infusor and exchanger220. This module 220 is used for delivery of large volumes of plasmasubstitute, blood substitute (e.g., stroma free hemoglobin) or wholeblood, optionally with special agents such as preservation orresuscitation drug cocktails. The module 220 can be provided in aseparate portable case. This module 220 will be connected to the venousside or first cannula means tube 74. The module 220 will includecontainers for blood, plasma substitutes and blood substitutes. Theblood, plasma substitutes or blood substitutes will be placed in areservoir 222 which is connected to the first cannula assembly means onthe venous side of the apparatus. The reservoir 222 is preferably madeof plastic and preferably of a ten (10) liter capacity. Tubing 224 isused to carry the blood, blood or plasma substitute from the reservoir222 to the first cannula tubing means 74 by means of a Y-connector 225.Also provided are means for mixing into the infused blood other fluidssuch as fluid resuscitators "FR", or plasma or plasma substitutes "P"with or without drugs to be administered by infusion. The module 220 canalso include kits for checking of hematocrit and activated clottingtime. Finally, a ten (10) liter plastic drainage reservoir 228 isprovided that can be connected at the patient side of the tubing 74 forcollecting blood from the patient when a rapid blood exchange from thearterial side is to be accomplished. A clamp 229 can also be providedbetween the drainage reservoir 228 and the Y-connector 225. This will beused in cases of severe rapid hemorrhage and in cases where thepatient's own blood is to be replaced as in suspended animation withblood washout and deep cooling.

The third module is the blood purifying module 240. Once emergencyresuscitation with circulation of adequate blood volume has beenaccomplished, one may want to detoxify the blood by one of several ways.This can be accomplished by attaching one of the commercially availableblood purifying units (e.g., hemabsorption filter and apheresisapparatus) rapidly and easily to the core unit. The driving force is thecore unit's blood pump. A sidearm 242 of the core unit's arterial lineis connected in parallel with the priming shunt circuit 150, to thefirst cannula assembly means 70. One option is a continuous low flowside stream as, for example, through a charcoal hemabsorption filter.Another example is that of intermittent withdrawal of increments of thepatient's arterial or venous blood for modification in a plasma or cellapheresis apparatus. The modified blood is returned by gravity into thefirst cannula assembly means 70.

The presently commercially available detoxifying devices that might beattached include those that could provide one of the followingtreatments: hemabsorption by means of a charcoal filter for example;hemofiltration (mostly for water removal); hemodialysis (artificialkidney); plasma and blood cell apheresis (e.g., Hemoneticsplasmapheresis unit); and extracorporeal heating or ultrasound or othernovel treatment of blood for killing bacteria or viruses. Removal of"sick" white blood cells is becoming a novel experimental therapy formultiple organ failure, including the postresuscitation syndrome.Exchange of the patient's "sick" plasma for fresh plasma or plasmasubstitutes, has been effective in some chronic conditions such asparalyzing polyneuritis and myasthenia gravis, for which the treatmentwith such a portable and miniaturized unit would become more readilyavailable.

The fourth module is the aortic balloon catheter shown onlyschematically in FIG. 3. This catheter is used (i) to stop lethalhemorrhage below the chest (ii) to permit experimental differentialperfusion, cooling or warming of heart, brain or viscera and (iii) forextracorporeal membrane oxygenation in lung failure with spontaneouscirculation. The catheter can be used independently of the CPB circuitto deliver medications or other fluids to the patient or can be used totake the place of the second cannula assembly means 128 to permitdifferential perfusion of various regions of the body, as will beexplained hereinafter.

Referring to FIGS. 4 and 5, the aortic balloon catheter of the inventionis shown. The outer tube 251 in which the catheter is positioned is notshown in FIG. 4 for clarity of illustration, but a cross-sectional viewof the outer tube 251 is shown in FIG. 5. The catheter is about sixtycentimeters long (for adult use) having a diameter of about 18-22 FrenchOD. The catheter is preferably thin walled and non-kinking. The catheterhas a first lumen 270 and a second lumen 271. Lumen 270 has an openinternal end 272 and an external end 274. The external end 274 of lumen270 forms part of the cannula assembly means (not shown) that is used toconnect the CPB machine or a drug or liquid source to the catheter.Lumen 271 also has an open internal end 273 and an external end 275.External end 275 also forms part of the cannula assembly means (notshown) that is used to connect the CPB machine or a drug or liquidsource to the catheter. It will be appreciated that multiple holes 276and 277 can be provided in the first and second lumens near therespective open internal ends 272 and 273.

The catheter also includes first pilot tubing 280 and second pilottubing 281. First pilot tubing 280 has an end that communicates with theinterior of a first balloon 282. Second pilot tubing 281 has an end thatcommunicates with the interior of a second balloon 283. FIG. 4 showsballoons 282 and 283 being deflated. FIG. 5 shows the balloons 282 and283 as inflated. In order to inflate the balloons 282 and 283, pumpmeans (not shown) which communicates with the ends of the pilot tubing280 and 281 provides a fluid, such as air, which is delivered to theballoons 282 and 283 via the respective first and second pilot tubingmeans 280 and 281. The pump means can include valves, regulators andgauges as is well known to those skilled in the art. The pump means canindependently control the inflation or deflation of the first and secondballoons so as to allow selective inflation or deflation thereof.

As can be seen in FIGS. 4 and 5, balloon 282 is positioned below theinternal open end 272 of lumen 270 and the second balloon 283 ispositioned below the open internal end 273 of lumen 271 but above theopen internal end 272 of lumen 270.

Referring now more particularly to FIGS. 5-9, the catheter in its outercovering 251 is shown as positioned in the aorta 285 of a human adult286. The outer covering 251 surrounds the lumens 270 and 271 and pilottubing 280 and 281 and is made of any suitable material known to thoseskilled in the art such as any resinous material. As was explainedhereinbefore, the catheter can be used in place of the second cannulaassembly means 128 in order to complete the CPB circuit to deliveroxygenated blood from the CPB apparatus (FIGS. 1-3). The catheter canalso be used independently of the CPB apparatus to deliver drugs orother fluids from a source (not shown) to the patient. It will beappreciated that the catheter is inserted into the femoral artery (notshown), similarly to the way that the second cannula assembly means 128is inserted into the patient.

FIG. 5 shows both first balloon 282 and second balloon 283 beinginflated. The first balloon 282 is positioned in the descending aorta287 below the brachiocephalic trunk 288 (which forms the rightsubclavian artery 289 and the right common carotid artery 290) as wellas below the left common carotid artery 291 and the left subclavianartery 292. The second balloon 283 is positioned in the ascending aorta293 and just above the aortic valve 294 and the coronary arteries 295.

Referring more particularly to FIG. 6, it will be seen that the cathetercontains lumens 270 and 271 as well as pilot tubing 280 and 281. Thelumens 270 and 271 and pilot tubing 280 and 281 are placed in thecatheter outer covering 251. The catheter is positioned in the aorta 285of the patient 286. When balloon 282 is inflated (FIG. 7), it sealinglyengages the interior wall of aorta 285 to block the aorta 285. Lumens270 and 271 as well as a pilot tubing 281 continue to extend beyondballoon 282. In this way, fluid can flow through lumens 270 and 271 pastballoon 282. Lumen 270 open internal end 272 is positioned in betweenballoons 282 and 283, so only lumen 271 and 281 remain in the catheteras shown in FIG. 8. The catheter 250 has a reduced diameter at thispoint. Finally, when balloon 283 is inflated (FIG. 9), it also blocksaorta 285. Fluid from lumen 271 can flow therethrough past balloon 283and out open end 273.

It will be appreciated that differential perfusion to the head and/orheart can be accomplished by using catheters. If neither balloon 282 and283 is inflated, a preferential supply of blood and/or medications canbe supplied to the arteries leading to the head, i.e., the rightsubclavian 289, right carotid 290, left subclavian 291 and left carotid292 (hereinafter referred to as "head arteries") and the coronaryarteries 295 (hererinafter referred to as "heart arteries") but theblood and/or drugs will also be circulated to the rest of the body.

If only first balloon 282 is inflated, a supply of blood or drugs willbe delivered to the head arteries and the heart arteries to selectivelyperfuse the head and heart as well as providing hemostasis in severehemorrhage below the thorax, as for example, the result of severe traumaor rupture of the abdominal aorta. If the catheter is used in place ofthe second cannula assembly means 128 when performing CPB as by usingthe CPB apparatus of the invention, it will be appreciated that thevenous blood withdrawn from the venae cavae of the patient will beoxygenated and returned directly to the head and heart arteries, with noblood being lost because of trauma below the thorax. The oxygenatedblood will be delivered to the heart and head and will return to thevenae cavae via the venous system. At this point the cycle begins againwith the venous blood being withdrawn from the patient's venae cavae bythe first cannula assembly means 70 into the CPB apparatus foroxygenation.

If only second balloon 283 is inflated, a supply of blood or drugs isdelivered only to the heart arteries. Blood can be circulated only tothe heart arteries in the case of head and/or lower extremity trauma.

If both balloons 282 and 283 are inflated, arterial perfusion and/ordelivery of medication can be achieved in three different compartments.The head can be perfused through lumen 270, the heart can be perfusedthrough lumen 271 and the rest of the body can be perfused by use of thesecond cannula assembly means 128 of the CPB apparatus.

It will be appreciated that these manipulations allow control of thecomposition and temperature of perfusion fluid (blood or medications) tothe heart, to the head and to the rest of the body independently. Thesemanipulations and combinations permit stopping bleeding in the head orthe rest of the body in case of trauma by selectively not perfusing thatparticular region of the body.

For differential perfusion, cooling, warming, or special fluid or drugadministration to heart and/or brain and/or viscera, the catheter isinserted fully, with its tip placed just above the aortic valve 294, andthe second balloon 283 inflated in the ascending aorta 293. Theascending aorta is eight to ten centimeters (8-10 cm) long in adulthumans. This insertion ideally should be by emergency fluoroscopy, butmight be possible by external measurements and the markings on thecatheter without fluoroscopy, or under incision with the chest open.

For suspended animation, to enable resuscitative surgery in"irreparable" injuries, one might start cooling the whole organismmoderately via the standard CPB circuit. When spontaneous heartbeat hasceased, the catheter is inserted in order to deliver differenttemperatures and solutions to heart, brain, and viscera. One can then atthe end of a deliberate arrest of one to two hours resuscitate, forexample, the heart before the brain.

For lung failure with spontaneous circulation (spontaneous heartbeat),both balloons remain deflated. The catheter is inserted into theascending aorta as an alternative to a regular nonballoon catheter ofthe same length. The catheter tip is placed into the ascending aorta 293in order to deliver variable low flow rates of oxygenated blood, whichin addition to the cardiac output from the left ventricle, achievesbetter oxygenation for heart and brain. A peripheral catheter wouldachieve this only for the lower part of the body.

In all usages of this device, the aortic balloon catheter would be usedinterchangeably or simultaneously with the standard short femoral arterycannula CPB circuit on the opposite side, from the apparatus (FIG. 3).

Insertion of the catheter through the femoral artery is preferred sincethe other option (its insertion through the axillary or neck) wouldencroach on the lumen of the cerebral blood flow.

For differential perfusion cooling and warming of the heart, brain, orviscera, there are now explorations ongoing concerning the relativetolerance of therapeutic deep hypothermia levels by heart and/or brainand/or viscera. There is a suggestion that temperatures near freezingare well tolerated by the brain, which would protect it against lack ofoxygen during deliberate circulatory arrest to facilitate surgery, whilethe same very low temperatures cannot be tolerated by the heart withouthurting it permanently. Also, the drugs most effective for brainresuscitation may differ from these most effective for heartresuscitation.

For use with the heart beating and lung failure, early use in lungfailure of low flow delivery of oxygenated blood into the ascendingaorta might make potentially injurious artificial ventilationunnecessary. Japanese investigators have called this treatment"extracorporeal lung assist" (ECLA). They used regular single lumencatheters for veno-arterial or veno-venous oxygen enrichment. This ideawas preceded by the use of somewhat higher flow delivery of oxygenatedblood into the ascending aorta in patients already with advancedpulmonary consolidation, in whom standard ventilator care cannotmaintain blood oxygenation. This has been called "extracorporealmembrane oxygenation" (ECMO). In the multipurpose use of the invention,with balloons deflated, merely a catheter delivering a modest adjustableflow of oxygenated blood added to spontaneous cardiac output, oftenneeded for many days, might sometimes "turn the tide" in progressivelung failure like "shock lung" or severe pneumonia.

Referring back to FIG. 3, the fifth module is a temperature samplingport 297. This optional adjunctive module is near the sampling ports ofthe core unit's first cannula assembly means 70 and second cannulaassembly means 128. Both would either contain an electrode for oxygentension monitoring, or an oximeter as now used percutaneously orinvasively in critical care. The arterno-venous oxygen value differencesand their relative changes will be used to guide the needed flow ratesto be set on the electrical console of the core unit, to providesufficient arterial oxygen transport for the organism's overall oxygenuptake.

It will be appreciated that a portable and modular cardiopulmonarybypass apparatus (CPB) has been provided. The CPB apparatus is portableso that it can be used at the scene of an accident or at the scene of apatient in cardiac arrest. The CPB can be used with several differentmodules for conditioning the blood, such as modules that include a heatexchanger, blood purifier, plasma blood cell apheresis and temperaturemonitor and with an aortic balloon catheter. The aortic balloon catheteris used to stop lethal hemorrhage below the chest, to permitexperimental differential perfusion and for extracorporeal membraneoxygenation in lung failure with spontaneous circulation.

Whereas a particular embodiment of the invention has been describedabove, for purposes of illustration, it will be evident to those skilledin the art that numerous variations of the details may be made withoutdeparting from the invention as defined in the appended claims.

What is claimed is:
 1. A method of inducing a state of suspendedanimation in a patient, comprising the steps of:(a) withdrawing bloodthrough a cannula introduced into a blood vessel of the patient; (b)controlling the temperature of said blood; (c) flowing said temperaturecontrolled blood through an arterial cannula introduced into a selectedarterial vessel of the patient for a sufficient time and at a sufficientflow rate to change the temperature of at least a portion of thepatient's body; (d) introducing an aortic balloon catheter into theaorta of the patient to establish fluid communication through thecatheter lumen between an external location and an aortic locationdisposed in a preferential flow relationship with a selected branchartery of the aorta; (e) positioning a balloon mounted on the exteriorof said aortic catheter at a balloon location spaced longitudinally fromsaid aortic location and inflating said balloon to resist blood flow;and (f) communicating fluid through said catheter lumen between saidexternal location and said aortic location.
 2. The method of claim 1,wherein:the branch artery is selected as the heart arteries.
 3. Themethod of claim 2, wherein:the step of positioning said balloon includespositioning it in the aorta between the head arteries and the heartarteries so as to cause said fluid communicated through said catheterlumen to preferentially flow to the heart arteries and said bloodcommunicated through said arterial cannula to preferentially flow to thehead arteries.
 4. The method of claim 1, wherein:the step of controllingthe temperature of said blood includes cooling it to a firstpredetermined temperature and flowing it through said arterial cannulafor a sufficient time and flow rate to cool the brain to a selectedtemperature.
 5. The method of claim 4, wherein:the step of controllingthe temperature of said blood further includes cooling it to a secondpredetermined temperature and flowing it through said catheter lumen fora sufficient time and flow rate to cool the heart to a second selectedtemperature.
 6. The method of claim 5, that includes:arresting theheart.
 7. The method of claim 5, wherein:said first predeterminedtemperature is less than said second predetermined temperature.
 8. Themethod of claim 5, wherein:said first predetermined temperature isgreater than said second predetermined temperature.
 9. The method ofclaim 6, that includes the steps of:(i) maintaining arrest of the heart;and (j ) performing surgery on the patient while the heart is arrested.10. The method of claim 1, that includes:flowing said controlledtemperature blood at a flow rate of up to ten liters per minute.
 11. Themethod of claim 1, wherein:the step of withdrawing said blood includesflowing it through a cardiopulmonary bypass pump apparatus.
 12. Themethod of claim 1, wherein:the step of withdrawing said blood includesflowing it through a heat exchanger.
 13. The method of claim 1,wherein:the step of withdrawing said blood includes flowing it through ablood oxygenator.
 14. The method of claim 1, wherein:the step ofcontrolling the temperature of said withdrawn blood includes cooling itapproximately five degrees Centigrade.
 15. The method of claim 1, thatincludes the steps of:(g) heating said withdrawn blood; and (h) flowingsaid heated blood through said catheter lumen for a sufficient time andflow rate to warm the heart to cause spontaneous heartbeat to begin. 16.The method of claim 6, that includes the steps of:(i) heating saidwithdrawn blood; and (j) flowing said heated blood through said catheterlumen for a sufficient time and flow rate to warm the heart to causespontaneous heartbeat to begin.
 17. The method of claim 15 or 16,wherein:the step of flowing said heated blood includes flowing saidheated blood through said arterial cannula to warm the brain.
 18. Themethod of claim 15 wherein:the step of heating said withdrawn bloodincludes heating said withdrawn blood sufficiently to raise itstemperature between approximately five to ten degrees Centigrade. 19.The method of claim 4, that includes:flowing said cooled blood throughsaid arterial cannula into the arterial vessel for a sufficient time andflow rate to induce mild hypothermia of the patient.
 20. The method ofclaim 4, that includes:flowing said cooled blood through said arterialcannula into the arterial vessel for a sufficient time and flow rate toinduce moderate hypothermia of the patient.
 21. The method of claim 4,that includes:flowing said cooled blood through said arterial cannulainto the arterial vessel for a sufficient time and flow rate to inducedeep hypothermia of the patient.
 22. The method of claim 4, wherein:thestep of introducing said aortic catheter includes making an incision inthe aorta; and introducing said aortic catheter through said incisioninto the aorta.
 23. The method of claim 4, wherein:the step ofintroducing said aortic catheter includes making incisions in the chestand the aorta; and introducing said aortic catheter through saidincisions into the aorta.
 24. The method of claim 1, wherein:the step ofintroducing said aortic catheter includes making an incision in aperipheral artery; and introducing said aortic catheter through saidincision into the aorta.
 25. The method of claim 24, wherein:saidperipheral artery is a femoral artery.
 26. The method of claim 24,wherein:said peripheral artery is an axillary artery.
 27. The method ofclaim 24, wherein:said peripheral artery is a carotid artery.
 28. Themethod of claim 1, wherein:said aortic location is in the ascendingaorta.
 29. The method of claim 1, wherein:said aortic location is in thedescending aorta.
 30. The method of claim 1, wherein:the step ofintroducing said cannula includes making an incision in a peripheralvein; and introducing said cannula into the blood vessel through saidincision.
 31. The method of claim 1, wherein:the blood vessel isselected as the vena cava.
 32. The method of claim 30, wherein:theperipheral vein is selected as a femoral vein.
 33. The method of claim1, that includes the step of:communicating a fluid through said cannulato the blood vessel.
 34. The method of claim 1, that includes the stepof:withdrawing a fluid through said catheter lumen from said aorticlocation.
 35. The method of claim 1, that includes the stepof:positioning a second balloon mounted on said aortic catheter in thedescending aorta and inflating said second balloon to resist blood flow.36. A method of differentially perfusing first and second regions of apatient's body, comprising the steps of:(a) positioning a first lumen ofan aortic balloon catheter to establish fluid communication between anexternal location and a first selected location in a flow relationshipwith a first branch artery of the patient's aorta leading to the firstregion; (b) positioning a second lumen of said aortic catheter toestablish fluid communication between said external location and asecond selected location in a preferential flow relationship with asecond branch artery of the patient's aorta leading to the secondregion; (c) positioning a first blood flow resisting balloon mounted onthe exterior of said aortic catheter in the aorta between the respectivesaid first and second branch arteries and inflating said first balloonto resist blood flow; (d) communicating a first condition fluid to saidfirst branch artery; and (e) communicating a second condition fluid tosaid second branch artery.
 37. The method of claim 36, that includes thestep of:(f) positioning a second blood resisting balloon mounted on theexterior of said aortic catheter in the aorta between said externallocation and said first branch artery and inflating said second balloonto resist blood flow.
 38. The method of claim 36 or 37, that includesthe step of:(g) communicating a third condition fluid to the aorta ofthe patient.
 39. The method of claim 36 or 37, thatincludes:communicating said third condition fluid to the aorta throughan arterial cannula received in an arterial blood vessel of the patientand extending to said external location.
 40. The method of claim 36 or37, that includes:positioning the respective said first and secondlumens in a preferential fluid flow relationship with the head arteriesand the heart arteries, respectively.
 41. The method of claim 39, foralso differentially perfusing a third region of the patient's body thatincludes:positioning said arterial cannula in a preferential fluid flowrelationship with selected branch arteries of the aorta leading to thethird region.
 42. The method of claim 41, that includes:selecting saidselected branch arteries to include visceral arteries of the patient.43. The method of claim 41 wherein:said third region includes the restof the body.
 44. The method of claim 38, that includes:selecting therespective said first, second and third fluids with respective first,second and third temperatures.
 45. The method of claim 44, wherein:saidfirst temperature fluid includes cooled blood, said second temperaturefluid includes blood cooled to a temperature selected to be cooler thansaid first temperature fluid and said third temperature fluid is cooledblood selected to be warmer than both of the respective said first andsecond temperature fluids.
 46. The method of claim 38, thatincludes:selecting the respective said first, second and third fluidswith respective said first, second and third compositions.
 47. Themethod of claim 36, wherein:said first selected location is in thedescending aorta of a human patient.
 48. The method of claim 36,wherein:said second selected location is in the ascending aorta of ahuman patient.
 49. The method of claim 36, wherein:the step of inflatingsaid first balloon includes inflating it to sealingly engage the aorticlumen walls of the aorta.
 50. The method of claim 37, wherein:the stepof inflating said second balloon includes inflating it to sealinglyengage the aortic lumen walls of the aorta.
 51. The method of claim 36,that includes the step of:deflating said first balloon.
 52. The methodof claim 37, that includes the step:deflating said second balloon. 53.The method of claim 36 or 37, that includes:withdrawing blood throughsaid first lumen.
 54. The method of claim 36 or 37, thatincludes:withdrawing blood through said second lumen.
 55. The method ofclaim 36 or 37, wherein the patient is an adult human, and wherein:saidsteps of positioning the respective said lumens include positioning themin the aorta of the adult human.
 56. A method of treating a selected oneof three body regions in a patient including the brain region, heartregion and rest of the body region, and comprising:establishing acardiopulmonary bypass circuit through the patient's blood vessels;arresting the heart; inserting an aortic balloon catheter into thepatient's aorta and inflating a balloon mounted on said catheter; andintroducing a selected fluid to a lumen of said catheter to establishpreferential flow to at least one of the body regions.
 57. The method ofclaim 56 that includes:positioning said balloon in the aorta to, wheninflated, establish preferential flow from said lumen to the brainregion.
 58. The method of claim 56 that includes:positioning saidballoon in the aorta to, when inflated, establish preferential flow fromsaid lumen to the heart region.
 59. The method of claim 56 thatincludes:positioning said balloon in the aorta to, when inflated,establish preferential flow from said lumen to the rest of the bodyregion.
 60. The method of claim 56 that includes:positioning the balloonto, when inflated, resist blood flow from the aorta to the region belowthe chest of the patient.
 61. The method of claim 56 thatincludes:maintaining the heart arrested for an hour.
 62. The method ofclaim 56 that includes:maintaining the heart arrested for two hours. 63.The method of claim 56 that includes:performing surgery on the patientwhile the heart is arrested.
 64. The method of claim 56 thatincludes:selecting and inserting said aortic balloon catheter with twolumens opening in their internal ends in respective longitudinallyspaced apart holes with the balloon positioned therebetween; positioningsaid balloon in the aorta to dispose one hole in preferential flowrelationship with the heart arteries and the other with the brainarteries; and flowing said selected fluid through one lumen and a secondfluid through the other lumen.
 65. The method of claim 64 thatincludes:flowing a third fluid in the patient's vascular system to therest of the body region.
 66. The method of claim 65 thatincludes:cooling the patient's blood to a first temperature and flowingit as said selected fluid to cool the brain; flowing blood at atemperature cooler than said first temperature as said second fluid; andflowing blood at a temperature warmer than said first temperature assaid third fluid to the rest of the body region.
 67. The method of claim56 for treating a patient who is hemorrhaging in one of said bodyregions and that includes:detecting the body region where thehemorrhaging is taking place and identifying that region as ahemorrhaging region; placing said balloon in said aorta to, wheninflated, resist blood flow through the aorta to said hemorrhaging bodyregion.
 68. The method of claim 56 that includes:controlling thetemperature of said fluid.
 69. The method of claim 56 thatincludes:selecting at least one of the body regions as the patient'sbrain region; and cooling the patient's blood and flowing it as saidselected fluid to cool such brain region.
 70. The method of claim 69that includes:cooling said blood to a temperature sufficient to, as itis flowed to the brain region, lower the temperature of the brain regionto near freezing.
 71. The method of claim 69 that includes:while flowingsaid blood to the brain region, flowing a warmer blood to the heartregion.
 72. The method of claim 69 that includes:while flowing saidblood to the brain region, flowing a cooler blood to the heart region.73. The method of claim 56 for treating a patient with lung failure thatincludes:positioning said catheter to establish preferential flowthrough said lumen to the ascending aorta; and selecting said fluid as aresuscitation fluid.
 74. The method of claim 73 that includes:selectingsaid fluid as oxygenated blood.